text: import unittest
  
  from solution import main
  
  
  class TestSolution(unittest.TestCase):
      def test_case_1(self):
          with open('case1_in.txt') as sample_input:
              case1_in = sample_input.read()
          with open('case1_out.txt') as sample_output:
              case1_out = sample_output.read()
  
          self.assertEqual(str(main(case1_in)), case1_out)
  
  
  if __name__ == '__main__':
      unittest.main()
  